Multi-tap connector



Jan. 26, 1965 J. c. SARAZEN MULTI-TAP CONNECTOR 5 Sheets-Sheet 1 Filed Sept. 17, 1962 INVENTOR. fimv J. JLQAZEA/ J. C. SARAZEN MULTI-TAP CONNECTOR Jan. 26, 1965 3 Sheets-Sheet 2 Filed Sept. 17, 1962 m T m V m \fOHN C SARAZE/Y A 7'TOE/VEY Jan. 26, 1965 J. c. SARAZEN 3,167,375

MULTI-TAP CONNECTOR Filed Sept. 17, 1962 3 Sheets-Sheet 5 5 1 III A i PIC-3,4

INVENTOR JOHN (I 5A RAzE/v A TTORNE' Y United States Patent ()fiice 3,167,375 Patented Jan. 26, 1965 3,167,375 MULTI-TAP CONNECTOR John C. Sarazen, White Plains, N.Y., assignor to Burndy Corporation, a corporation of New York Filed Sept. 17, 1962, Ser. No. 224,172 1 Claim. (Cl. 339-99) My invention relates to a multi-tap connector and, more particularly, to a connector provided with insulation piercing contacts.

This connector may be used to tap into selected conductors of multi-conductor cable such as is presently used, for example, to interconnect telephone director units. Connectors for such cable may be called upon at times to tap runs of up to 250 conductors.

It is among the objects of the present invention to provide a multi-tap connector that may be speedily installed with little skill and experience; that is of the smallest practical size; that is reliable and of minimum cost; that will not cause damage to the tapped conductors; that will straddle the existing cable and require little standoff distance from the bulkhead; that may be adapted to provide a tap-off cable that meets an existing cable run at a given angle to thereby eliminate any necessity for additional standoff distance to accommodate the tap-off cable bending radius; and that employs plural systems of strain relief, giving assurance of high reliability and maintenance free service.

I accomplish these and other objects and obtain my new results as will be apparent from the devices described in the following specification, particularly pointed out in the claim, and illustrated in the accompanying drawings in which:

FIGURE 1 is a front perspective view of my connector shown mounted to a bulkhead.

FIGURE 2 is a perspective view of the underside of the same with the parts in exploded position.

FIGURE 3 is a section view taken along line 3-3 of FIGURE 1.

FIGURE 4 is a perspective view of a single cable tap contact and conductor.

FIGURE 5 is a front elevation of another form of cable tap contact.

Referring more in detail to the drawing, reference numeral 1t) designates the connector housing which in the drawing is shown to be roughly square in shape with the corners modified to save space and give a pleasing hexagonal appearance. Entrance and outlet portals 12 and 14 are provided in diagonally opposite corners of the housing for accommodating and seating the cable 16.

Bores 24 are provided in enlarged sections 23 of side walls 22 to accommodate mounting screws 26 or 27 for securing the housing to a panel wall, or other support structure such as 18. A back plate may be provided for additional protection of the contents of the housing interior. The plate may be directly fastened to the housing independently of wall or panel mounting by providing bores 24 with internal threads to engage screws 26.

Within the housing a contact block 28 is mounted, having projecting rows of spaced apart ribs 30 providing seats 32 therebetween, into which the insulated conductors 34 are placed. At the bottom of the seats contacts 36 are positioned for establishing contact with the conductors.

Mounting screws 38 are provided at both ends of the contact block for securing the block in position.

In the embodiment illustrated, two axially spaced apart rows of seated contacts 36 are provided; the cable conductors 34 are paired and stacked two high above the contacts 36 in each row, and are twisted so that the bottom conductor in one row is the top conductor in the other, as shown in FIGURE 2. Each contact taps only the bottom conductor in its row. Thus, by tapping two conductors in the transverse width of a single conductor a fifty percent reduction in the distance between outermost ribs 30 is accomplished and a substantial reduction in the overall width of the connector is made possible.

A pressure bar 40 is mounted over the screws 38 through apertures 42, for providing sufiicient pressure to the conductors to establish the tap connections. Pressure is transmitted to the bar 40 by tightening nuts 49 threaded onto screws 38. As the bar is forced toward contact block 28, teeth 44 mate with the teeth or ribs 30 of the contact block, forcing the conductors further into the seats 32 and against the contacts 36. A polarizing pin 4-5 may be provided in the contact block for engaging aperture 47 to insure proper orientation of the pressure bar thereon.

The front surface 48 of the housing 10 is provided with an openfaced projection or extension 50, into which the contact block 28 extends to form plug receptacle 54. The insulation piercing contacts 36 embedded in or otherwise secured to block 28, terminate in spring contacts 56 positioned in sockets 58, for engagement with a connecting plug, not shown.

Details of a contact construction of one type are shown in FIGURE 3. The contact 36 is formed with a chisel edge, as at 60. The contact is made of metal having sulficient hardness to cut through the insulation 62 but soft enough to be deformed by the metal conductor 34a. Electrolytic copper similar to that used in the conductor itself will meet these requirements.

As the conductor is forced against the contact, the edge pierces the insulation and is then deformed into a seat 64 for the conductor. Contact pressure is maintained by the pressure bar 40.

in the contact 3612 shown in FIGURE 5, sheet metal is used in the form of a plate. It is provided with a V-guide or opening 66 large enough to accommodate the insulated conductor. The tapering edge 68 is sharpened to cut into the insulation, allowing the metal conductor to be snap fitted into place between opposed seats 70 under contact pressure. Additional cutouts 72 may be provided to afford slight resilient spreading of seats 70 when a conductor is inserted.

By my unique construction, the connector straddles the existing cable forming a saddle design. Little additional standoff distance is required from the bulkhead.

The axis of plug receptacle 54 is oriented as shown so that the tap-off cable enters parallel to the existing cable run, thereby substantially reducing the space requirements of the connector.

The design incorporates two distinct systems of strain relief giving assurance of high reliability and maintenance free service. As shown in FIGURE 2, the tapped conductors 34 follow a substantially straight level path through the connector, passing over the contact block. The untapped conductors follow a longer path around the contact block on opposite sides of mounting screws 38 thereby creating slack in the tapped conductors, which may be taken up in the central space of block 28. It can be seen therefore, that even if both ends of the cable are pulled simultaneously it is impossible to create any strain on the tapped conductor or contacts.

The second strain relief is provided by the cable being compressed in the entrance and outlet portals 12 and 14 when the connector is fastened to a support surface, or when the backplate 20 is attached.

It should be noted that both of these strain reliefs are achieved without additional parts or increase in cost.

For additional versatility, an optional backplate has been illustrated. By using the backplate, the connector may be used in situations where support surface mounting is inconvenient. Naturally the backplate may be used with the support surface mounting if desired to provide additional electrical isolation or sealing.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and therefore I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claim, and by means of which objects of my invention are obtained and new results accomplished since the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects and accomplish these results.

I claim:

A tap connector for a cable having a plurality of pairs of insulated conductors, comprising: a housing having an extrance and an exit port for said cable; a contact block of insulating material extending across the path of said cable within said housing; a first plurality of substantially parallel spaced apart ribs on said contact block forming a plurality of parallel channels for receiving individual pairs of said conductors and extending across the path of said cable; a second plurality of substantially parallel spaced apart ribs on said contact block axially spaced from said first plurality of ribs and likewise forming a plurality of parallel channels for receiving individual pairs of said conductors; each of said channels being dimensioned to receive and support the individual conductors in each pair in one-above-the-other relationship, only; a plurality of sharpened contacts disposed Within said channels for penetrating the insulation of and engaging one of the conductors of each pair of conductors disposed in each of said channels; said first plurality of ribs being axially spaced from said second plurality of ribs a distance sufiicient to permit transposition of the vertical position of the conductors in a given pair between a channel formed by said first ribs and a channel formed by'said second ribs, whereby one of the conductors in a pair may be engaged by the contact in a first channel and the other conductor in that pair may be engaged by the contact in a second channel.

References Cited in the file of this patent UNITED STATES PATENTS 698,233 Thomas Apr. 22, 1902 1,971,019 Slade Aug. 21, 1934 2,292,236 Martin d. Aug. 4, 1942 2,360,444 Pollock Oct. 17, 1944 2,574,608 Ziph Nov. 13, 1951 2,705,783 Greco Apr. 5, 1955 3,027,536 Pasternak Mar. 27, 1962 van-.1 

